Accommodating device for thermal transient expansions

ABSTRACT

An accommodating device for thermal transient expansions in an expander  ene wherein a configured valve support includes a spring-nut arrangement for controlling and minimizing the force changes due to the temperature variations of the valve because of the hot gases passing therethrough. This results in a consistent valve performance.

STATEMENT OF GOVERNMENT INTEREST

The invention described herein may be manufactured and used by or forthe Government of the United States of America for governmental purposeswithout the payment of any royalties thereon or therefor.

BACKGROUND OF THE INVENTION

This application is co-pending with my three other patent applications;Ser. Nos. 720,313; 720,485; and 720,490 and having the same filing dateof Sept. 3, 1976 and relating to a rotary expander engine of the Wankeltype describing and claiming various aspects thereof.

This invention relates to accommodating devices and more particularly toan accommodating device for thermal transient expansions in an expanderengine of the Wankel type.

A conical shaped hot working fluid rotary valve has been used inswashplate type torpedo engines for many years. The forces exertedbetween the valve's mating surfaces can vary widely as the materialsupporting and referencing the valve to some common ground point expandsand contracts under the influence of transient temperature gradientsexisting from the time of starting of the engine to the time anequilibrium is reached. The variations in the forces adversely affectperformance of the valve with respect to leakage or friction power loss.It is thus desirable to have a compensating system to maintain aconsistent valve performance.

SUMMARY OF THE INVENTION

An accommodating device according to the teachings of subject inventioncomprises a spring-nut arrangement which is housed in the supportassembly of an inlet valve and is referenced to a common ground. Anythermal expansions of the inlet valve and/or combustion chamber arecompensated by the spring resulting in a consistent performance of theinlet valve.

An object of subject invention is to achieve a consistent performance ofthe inlet valve of an expander engine.

Another object of this invention is to accommodate for the thermalexpansions of the inlet valve due to hot working fluid passingtherethrough.

Still another object of subject invention is to accommodate for theexpansions of the combustion chamber of an expander engine caused by theworking fluid under high temperature and pressure produced therein orbrought inside the combustion chamber from an external source.

Other objects, advantages and novel features of this invention willbecome apparent from the following detailed description of the inventionwhen considered in conjunction with the accompanying drawings wherein:

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a multi-cross sectional view of an expander engine wherein anaccommodating device of subject invention is used;

FIG. 2 is a magnified view of a part of the expander engine shown inFIG. 1 showing the spring-nut combination in a relaxed position; and

FIG. 3 is a view similar to the one shown in FIG. 2 with the spring-nutarrangement in a strained position.

DESCRIPTION OF A PREFERRED EMBODIMENT

Referring to the drawings wherein like reference characters designatelike parts throughout the several views, and more particularly to FIG. 1thereof, a multi-cross sectional view of expander engine 10 using anaccommodating device is shown. As shown in FIG. 1, male part 12 of inletrotary valve 14 is a part of combustion chamber 16 as housing structure78 is screwed and locked to male part 12. The female part 52 of valve 14is a part of the rotating assembly of expander engine 10 and is firmlyfixed to rotating housing chamber 30. The rotating members arereferenced to the support structure 126 through a thrust bearing. Themale part 12 of inlet valve 14 is referenced to support structure 126through a spring 114 and nut 116. Nut 116 permits changes in the normalforce between the mating surfaces of male member 12 and female member 52of inlet valve 14 while spring 114 allows changes in the axial length ofthe members involved, which are influenced respectively by thetemperatures of hot working fluid, water and exhaust gas, with minimumchange of force. Spring 114 is preferably a stacked Bellville spring andits spring constant can be changed according to the requirements of theexpander engine. FIG. 2 illustrates the situation when spring 114 is inits unstrained or relaxed condition and FIG. 3 illustrates when spring114 is in a strained condition. These figures indicate the way thespring-nut arrangements accommodate for the thermal transients of thevalve and/or combustion chamber.

Briefly stated, an accommodating device to compensate transient thermalexpansion in an expander engine, includes a spring-nut arrangement towhich the rotating part of the inlet valve is referenced. Any changes inthe dimensions of the combustion chamber or the rotating valve arecompensated by the spring-nut arrangement, thus insuring consistentvalve performance.

Obviously many modifications and variations of the present invention arepossible in the light of the above teachings. As an example, the springused in the accommodating may be other than a Bellville spring.Furthermore, the spring constant may be varied as required for aparticular machine. It is therefore understood that within the scope ofthe appended claims the invention may be practiced otherwise thanspecifically described.

I claim:
 1. An accommodating device for compensating thermal transientexpansions in a rotary engine which comprises:a housing assembly havinga first end and a second end; an elongated combustion chamber beingmounted in said housing, said chamber having a first end and a secondend; a pintle valve assembly being detachably mounted to said combustionchamber at the first end thereof; an inlet valve having a stationarymale part being connected to said combustion chamber at the second endthereof and a rotatable female part being secured to the rotatingmembers of said expander engine; a keying means mounted in said housingassembly for providing a reference ground for said expander engine; anut member being demountably engaged to said housing assembly at thefirst end thereof; and a spring member being mounted between said nutmember and the first end of said housing assembly and said spring memberbeing in contact with said combustion chamber.
 2. The accommodatingdevice of claim 1 wherein said spring is a Bellville spring.
 3. Theaccommodating device of claim 2 wherein said combustion chamber has aliner mounted therein along the walls thereof.
 4. The accommodatingdevice of claim 2 wherein said expander engine further includes arotatable housing chamber and a rotatable rotor being attached to therotatable male part of said inlet valve.
 5. The accommodating device ofclaim 2 wherein said expander engine further includes a stationary crankshaft mounted thereon.